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PROTON AP 1000 Stereo Pre-Preamplifier w/ Manual **SERVICED**. Good pre owned condition. It has been tested and works and sounds great. This was in my personal collection but I went with a moster receiver now. It has a few scratch marks on the case. It has had the Volume Pot & Bass Pot replaced. It has had all the pots cleaned and lubed with deoxit. Please see photos. Thanks
This is a fair ask at US$499: it lands exactly on the median of three comparable listings, well above the US$407 25th percentile but below the US$599 75th percentile. It is not a bargain at this price, but neither is it stretched—assuming the unit is fully functional and presentable.
The AP-1000 is a capable vintage preamp with dual-mono power supplies, useful MM/MC phono support, tone-control defeat, and dedicated subwoofer/high-pass outputs for flexible system integration. Its phono stage and connectivity are the main attractions, making it a particularly sensible choice for a vinyl-based system or bi-amping setup. With unknown condition, confirm quiet controls, reliable input switching, both phono modes, and a clean volume pot before paying the median; a tested, original example would justify the ask.
Independent perspective — not a price guarantee. Always verify condition, accessories and provenance before purchase.
Proton Electronic Industrial Co., Ltd. emerged from Taiwan in 1981, establishing its base in Banciao, Taipei-Hsien, as a manufacturer targeting the U.S. consumer audio market with high-quality components. Linked to Fulet Electrical, which produced notable NAD amplifiers, the brand launched around 1984 to expand into consumer electronics, including acclaimed TV monitors like the 600M and 602M models. By 2009, it remained active, building on a heritage of precision engineering from shared facilities with brands like NAD and Dynaco.
The company focused on premium hi-fi gear optimized for real-world performance, emphasizing tuners, receivers, amplifiers, and integrated systems that drove everyday loudspeakers with exceptional clarity. While not delving into headphones or cables, Proton's lineup prioritized robust playback under practical listening conditions, from radio reception to vinyl and cassette sources, earning praise for its engineering rigor in the 1980s.
Proton holds a solid reputation in vintage hi-fi circles as a mid-tier powerhouse, favored by collectors for its reliable, high-value sound that punched above its price point. Positioned as an accessible alternative to elite brands, it appeals to discerning buyers seeking durable, no-nonsense performers rather than boutique exotica, with ongoing interest in its schematics and restored units.
See all Proton listings on RADAR.
